1. Field of the Invention
This invention relates to rectal specula and, more particularly, to a speculum for use with colon lavage apparatus.
2. Description of Related Art
Devices are known for lavaging the lower intestinal tract of patients suffering from colitis and similar ailments. These devices commonly employ a speculum for directing water or a treating fluid into the patient's colon and subsequently allowing the discharge of fluidized waste matter. One type of rectal speculum used with a colon lavage apparatus is formed of a pair of concentric tubes; an inlet tube carries the water into the patient's rectum and colon and a discharge tube allows fluidized waste matter to flow out.
Another type of speculum has a main tube-like body. In order to facilitate insertion of such a speculum into the patient's rectal canal, to decrease the patient's discomfort and possible pain and to avoid possible injury to the patient's intestinal tract, the speculum is usually used in conjunction with an obturator. A typical obturator is an elongated rod having a tapered cone-like portion at one end and a handle portion at the opposite end. The cone-like portion of the obturator is inserted through the hollow interior of the speculum from the proximal end to extend from the distal end. The cone-like portion closes the open end of the speculum and facilitates insertion of the speculum, minimizes discomfort and the likelihood of injury is reduced. Once a speculum is in place, the obturator is removed by gripping the handle portion and withdrawing the obturator from the speculum. Thereafter, a waste matter discharge conduit is attached to the distal end of the speculum.
Conventional specula suffer from a number of drawbacks. In particular, a speculum having a concentric tube structure is difficult and expensive to manufacture and it is inconvenient to clean and maintain. Generally, it is too expensive to manufacture and discard as a single use device. Furthermore, the process of attaching a discharge hose or conduit to the distal end of the tube type speculum after removal of the obturator creates discomfort and can be painful since the proximal end of the speculum is free to rock or slide in the patient's rectum during attachment.
In an effort to solve the first drawback of concentric tubes, the speculum described and illustrated in U.S. Pat. No. 4,712,536 includes an unobstructed main tube having a distal end for insertion into a patient's rectum and a proximal end connectable to a conduit. An inlet tube extends laterally from the main tube to introduce water or a cleansing fluid into the speculum and the patient's colon. To assist in attaching the conduit, a thumb rest is provided to facilitate stabilizing the speculum during such attachment.
U.S. Pat. No. 4,943,285 describes and illustrates an improved single tube speculum having an undulating surface for gripping engagement by the patient's rectal sphincter muscle during use of the speculum. Additionally, a water or treating fluid inlet is set at an angle with respect to the speculum to direct the fluid toward the proximal end of the speculum.
Both of the specula described above define an inlet opening at the distal end. To ease insertion, an obturator is employed which projects a cone-like element from the inlet and which serves as a guide to ease penetration and expansion of the anus and colon to receive the speculum. The obturator includes a handle disposed at the proximal end of the speculum. This handle is gripped to withdraw the obturator from the speculum after insertion. Because of the requirement for removal of the obturator through the proximal end, the conduit for the waste matter must be attached after insertion of the speculum. The process of attaching the conduit to the speculum may be painful and usually incurs discomfort.